Many organizations that own and use respirators and/or protective masks have a need to periodically test the equipment to confirm their adequate operation. Many such organizations already possess equipment capable of performing certain aspects of a respirator performance test, such as an aerosol detector or a particle counter. The aerosol detectors and particle counters are used in the testing of respirators to “challenge” the fit and integrity of a respirator mask. The challenge test typically includes subjecting the respirator or portions thereof to a fine aerosol and measuring the concentration of particles that penetrate into the respirator. Accordingly, such organizations may prefer to acquire only the accessory equipment ancillary to the aerosol detector/particle counter to reduce procurement costs.
Respirator testing often utilizes a so-called “head form” upon which the respirator is mounted to test the performance. The use of an inflatable member to provide a positive seal against the portion of the respirator mask that seats against the user's face is known. The inflatable member provides a seal regardless of the fit of the mask against the head form. Any leaks detected are then known to be due to leaks in the mask, not leaks in the fit.
U.S. Pat. No. 5,808,182 to Stumpf, the disclosure of which is hereby incorporated by reference herein in its entirety except for terms expressly defined therein, discloses a “covering” that covers a portion of a head form and is inflatable through a port on the head form. The covering of Stumpf comprises a wide, flexible band with transitions areas near the edges of the band that are sealed against the head form. Accordingly, the transition area must be constructed pressure tight to guarantee inflation of the covering. Stumpf does not disclose how these transition areas are to be made pressure tight.
U.S. Pat. No. 7,343,783 to Tilley, which is also hereby incorporated by reference herein in its entirety except for terms expressly defined therein, discloses an “inflatable seal” that is disposed in a recess on a single portion of a head form. Tilley offers no details on the construction of the inflatable seal, nor how the inflatable seal is secured within the recess. However, an embodiment of the Tilley disclosure is commercially available as part of the TDA-99B Respirator Function Tester, marketed by Air Techniques International of Owings Mills, Md., USA. The inflatable seals used in the TDA-99B comprise a seam that is sealed with an adhesive, and also an inlet tube that is inserted through an opening or slit in the inflatable seal and sealed using a patch and adhesive. The adhesives in the inflatable seal of the TDA-99B necessitates additional curing time in the manufacturing of the inflatable seal, and also additional quality assurance steps to check the integrity of the inflatable seal and the inlet tube.
Various components of a respirator test system require periodic calibration and maintenance to assure competent results. Such calibration and maintenance can require removal of the individual sensors, shipping of the test unit, or switching equipment and/or test fixtures to accommodate field calibration that adds to the bulk of the respirator test system.
Organizations involved in the testing of respirators would welcome a respirator test accessory that complements already existing aerosol detection equipment and eases the burdens on equipment and personnel with respect to calibration and maintenance. Manufacturers of such test accessories would welcome an assembly process that reduces the dependence on adhesive seals and the time and quality assurance testing attendant thereto.